The ratchet clutch is one of one-way clutches, and can be divided into two types: an external engagement ratchet clutch and an internal engagement ratchet clutch. The traditional ratchet clutch realizes the function of transferring a torque in one rotating direction and idling in another direction through a mechanism composed of one ratchet and a plurality of pawls. When the ratchet type one-way clutch rotates in the idling direction, the pawls slide over a top tooth surface of the ratchet, so that an outer ring and an inner ring idle relatively. When the ratchet type one-way clutch rotates in a locking direction, the pawls and a tooth slot of the ratchet are embedded, and the one-way clutch becomes locked so as to transfer the torque between the inner ring and the outer ring.
In the ratchet type one-way clutch with traditional structure, when the one-way clutch rotates in the idling direction, the pawls slide over the tail end of the top tooth surface of the ratchet and knock the surface of the ratchet under the effect of an elastic element, and make a sound. Then, the pawls continue to slide to the top tooth surface of the next ratchet and continue to slide over the tail end of the top tooth surface of the next ratchet. Therefore, when the ratchet type one-way clutch rotates in the idling direction, the pawls will continuously knock the surface of the ratchet and make a sound, and the elastic element will continuously expand and contract and generate energy loss. This process will increase the wear of the pawls and the ratchet and reduce the service life of the elastic element.